Synthesis of MIL-88B(Fe) as an efficient catalyst for boosting phenol and tetracycline removal in a heterogeneous sono-Fenton process

This study investigated the removal of the organic pollutants phenol and tetracycline (TC) from wastewater using the iron-based metal-organic framework (MOF) catalyst MIL-88B(Fe) in a heterogeneous sono-Fenton process. The morphological and structural properties of the synthesized MIL-88B(Fe) catalyst were comprehensively characterized using advanced techniques, including FE-SEM, EDS, FTIR, XRD, BET, UV-Vis DRS, EIS, TOC, and zeta potential analysis. To optimize the removal efficiency of the target pollutants, a comprehensive parametric study was conducted. The optimization results revealed high removal efficiencies within a 60 min process: 97.4% for phenol (10 mg·L -1 , pH 7.5, 9.8 mM H 2 O 2 , and 0.1 g·L -1 of catalyst) and 95.3% for TC (30 mg·L -1 , pH 11, 3.92 mM H 2 O 2 , and 1 0.1 of g·L -1 catalyst), both achieved at an acoustic power density of 62.76 W·L -1 . The calculated synergy index values of 2.18 and 1.92 for phenol and TC removal, respectively, confirmed strong coupling among US, H 2 O 2 , and MIL-88B(Fe). Kinetic analysis using the Langmuir-Hinshelwood model indicated that a surface-mediated reaction, rather than bulk-phase radical attack, is the dominant mechanism. The results confirmed that OH ● and h + were the dominant reactive species, while played a secondary role. In addition, the sonocatalyst showed robust reusability and stability over four successive recycling cycles. These findings highlight the potential of the MIL-88B(Fe) catalyzed heterogeneous sono-Fenton process as an effective technology for treating wastewater containing persistent organic pollutants. • MIL-88B(Fe) enabled high-efficiency sono-Fenton degradation of phenol (97.4%) and TC (95.3%). • A mechanistic reactive-adsorption model outperformed empirical fitting via L-H kinetics. • Energy-normalized rate constants were established to facilitate process scale-up. • Synergy was disentangled into mass-transfer enhancement and intrinsic catalytic turnover. • The study meticulously optimized key operational parameters. • The sonocatalyst solved the recovery problem and represented high reusability.